Wei wants to expand his drug dealing business to over Blaine County, and sends his son and his son's translator to check Trevor Philips' business as a potential partner, but after an Aztecas attack on Philips' meth lab, they decide to partner with the O'Neil brothers, who are later slaughtered by Trevor due to this decision.

Wei sends his men to capture Trevor when the latter heads to Ludendorff, North Yankton. They fail to capture Trevor, but manage to take Trevor's friend Michael De Santa (who they believe to be Trevor's boyfriend, due to the time they spent living together in Trevor's trailer) as a hostage. Wei phones Trevor and threatens to kill Michael, but due to a certain event, Trevor ignores Wei's threats.

Wei takes Michael to a meat factory, where he tries to unsuccessfully interrogate Michael, and orders to kill him. Michael, however, is saved by his protege Franklin Clinton.

In the game's ending, Franklin is left with a choice to either kill Michael or Trevor, or to side with them as they attack all of their enemies ("Deathwish"), including Wei Cheng. If the player chooses the "Deathwish" ending, Franklin will drive to the beach club in Pacific Bluffs, where Wei Cheng is located, and kill him.

Trivia

Per chinese naming custom, Wei Cheng and Tao Cheng's names are incorrectly constructed. In Chinese naming custom, the family name comes first, while the given name comes last. During the mission Fresh Meat, Trevor identifies that Wei and Tao are from Yangshan in China, meaning they were born in Chinese soil, where the naming custom must be upheld by law. Thus, the correct way for them to be named would have been Cheng Wei and Cheng Tao.